Phosphodiesters serve as potentially tunable aglycones for fluoro sugar inactivators of retaining beta-glycosidases

2-Deoxy-2-fluoroglycosides bearing dibenzyl phosphate and phosphonate aglycones were synthesised and tested as covalent inactivators of several retaining alpha- and beta-glycosidases. beta-D-Gluco-, -manno- and -galacto-configured benzyl-benzylphosphonate derivatives efficiently inactivated beta-gluco-, beta-manno- and beta-galactosidases, while alpha-gluco- and alpha-manno-configured phosphate and phosphonate derivatives served instead as slow substrates.